Neuroblastoma is the most frequent malignant tumor in neonates. Prenatal sonography gives us great advantage in the diagnosis of congenital malformations and malignant tumors before birth. However, reported cases of prenatally diagnosed neuroblastoma are rare. The prenatal diagnosis of neuroblastoma may confer the advantages of early diagnosis of the tumor, as well as offering the potential for early therapy and improved survival because of the inverse relationship between patient age and survival. We experienced three cases of prenatally and postnatally diagnosed neuroblastoma in our institute. Two neuroblastomas were diagnosed at third trimester by prenatal sonography. In another case, the fetus was suspected to have a congenital cystic adenomatoid malformation of the lung prenatally, but finally diagnosed to have a neuroblastoma after birth. Adrenal masses were completely resected postnatally and pathologically confirmed to be neuroblastomas.